The expression \( \frac{B}{\mu_0} \) represents a quantity related to magnetic fields.
The dimensions of \( B \) (magnetic field) are [M T\(^{-2}\) A\(^{-1}\)], and the dimensions of permeability \( \mu_0 \) are [M L\(^{-1}\) T\(^{-2}\) A\(^{-2}\)].
Therefore, the dimensions of \( \frac{B}{\mu_0} \) are [M A L T\(^{-1}\)].
Consider the following two reactions A and B: 
The numerical value of [molar mass of $x$ + molar mass of $y$] is ___.
Consider an A.P. $a_1,a_2,\ldots,a_n$; $a_1>0$. If $a_2-a_1=-\dfrac{3}{4}$, $a_n=\dfrac{1}{4}a_1$, and \[ \sum_{i=1}^{n} a_i=\frac{525}{2}, \] then $\sum_{i=1}^{17} a_i$ is equal to
